Well casing gun perforator



Aug. 28, 1951 J; o. Tow v 2,565,789

WELL cAsING GUN PERFoRAToR Filed Aug. 2s, 1947 fia I7 '9a' 42a lwentor JA MES 0. TOW

Patented Aug. 28, 19151 WELL CASING GUN PERFORATOR James 0. Tow, Huntington Park, Calif., assigner to McCullough Tool Company, Los Angeles, Calif., a corporation of Nevada Application August 23, 1947, Serial No. 770,232

(ci. isi- 0.5)

2 Claims. l

This invention relates to guns of the type employed for perforating casing in wells by shooting projectiles therethrough, and relates in particular to a perforating gun having a separate magazine for powder charges.

It is an object of the invention to provide a perforating gun having a body equipped with radially extending barrels to receive projectiles, and having a chamber communicating with the inner ends of these barrels which chamber is adapted to receive a magazine which carries the powder charges for propelling the projectiles from the barrels when the gun is fired. A feature of the invention is that the arrangement of cooperating parts contributes to safety in handling of the gun for the reason that the powder chambers of the magazine may be loaded and kept separate from the gun body which has the projectiles therein, until such timey as assembly of the gun is required so that it may be in condition for lowering into the well.

It is a further object of the invention to pro` vide a well casing perforating gun having a body with barrels to carry the projectiles and an insertable magazine which carries all of the powder charges reouired for ythe ring of the gun. The powder charges for propelling the projectiles 'may be fired by any of the known electrically or mechanically actuated firing means, but in the simple form of the invention shown herein the propellant charges are fired through use of ignition passages which may be arranged to carry the ignition effect, such as flame and pressure, to the powder chambers of the magazine.

It is an object of the invention to provide a perforating gun comprising a body and a replaceable magazine which, due to its relative simplicity, may be replaced at small cost compared to the total value of the perforating gun.

Further objects and advantages of the invention may be brought .out in the following part-of the specification, wherein details of several forms of the invention are described for the purpose of fully disclosing the principles of the invention without limiting the scope thereof set forth in the appended claims.

Referring to the drawing which is for illustrative purposes only,

Fig. 1 is a sectional view showing a preferred an alternative arrangement wherein the inner ends of the projectiles extend into the powder chambers.

Fig. 4 is a cross section showing a form of the invention wherein the ignition passages are formed in part by spaces provided between the internal wall of the gun body and the external wall of the magazine.

Fig. 5 is a fragmentary sectional indicated by the line 5-5 of Fig. 4.

In the form of the invention shown in Figs. 1 and 2, the perforatinggun is provided with a. cyindric axially velongated body I 0 having an axial bore II defining in the body I0 an axially elongated space referred to herein as the magazine chamber I2. The'lower end of the bore II may be permanently' closed if desired, as by means of a screw plug I3, and the upper end of the bore II may be left open, this upper end of the bore II being covered when the perforating gun is assembled by a screw cap I4. The cap I4 is provided with a 'rope socket vI 5, by which the perforating gun may be connected to the lower end of an electrified cable I6 .of the type normally employed for lnwering electrically operated devices into wellssuch cables I6 having at least one internal insulated yconductor within its outer cable sheath.

The body I0 has a purality of radial bores forming radial barrels I'I to receive projectiles I8. A magazine I9 comprising a cylindric metal bar is disposed in the magazine chamber I2 of the body I0. The external diameter of the magazine I9 is slightly less than the internal diameter of the body I0, so'that themagazine I9 may be slid in and out of the chamber I2. The magazine I9 is oriented withinl the chamber I2v by view taken as aligning means consisting of an interengagement between the upper portionv of the body I0 and the upper portion of the magazine I9. The aligning means is shown as a keyway 20 in the upper portion of the body IU adapted to be en f gaged by a pin 2|, which projects from the upper portion of the magazine I9. The magazine I9 has therein a plurality of powder chambers 22 in cooperative relation to the barrels I1. These powder chambers 22 are formed by openings 23 drilled inthe magazine `I9 in axial alignment withthe respective barrels I1. The openings 23. however, do not extend entirely through the magazine I9 from side toside thereof, but a thin wall 24 is left at the front end of each opening 23 to confront the rear end of a'projectile I8. After propellant charges 25 are placed in the powder chambers 22, the rear ends of the powder chambers are closed by plugs 26 which may be formed from rubber compound, and as shown at 23a. metal discs may be placed at the rear ends of the plugs 2l.

At the upper end of the magazine Il there is a recess 21 defining at its lower end a priming charge chamber 28 to receive a priming charge 29 of powder ignitable by an electrically actuated fuse 30 carried in the lower end of a plug or fuse holder 3| which enters the upper part of the recess 21 when the gun body I0 is screwed into the cap I4. From the cable I8, an electrical conductor 32 is carried through the fuse holder 3| to the fuse 3|! which, in accordance with accepted practice, may be grounded with the cap I4, which is in turn grounded with the sheath of the cable I6. From the priming charge chamber 28, an ignition passage 33, of small diameter, is extended within the magazine i9 to the uppermost powder chamber 22 and small diam- `eter ignition passages 34 connect the powder chambers 22 in series so that when, by electrical energization, the fuse 30 is caused to ignite the priming charge 29, the ignition eect from the tiring of the priming charge 29, such ignition effect consisting of iiame and/or pressure, is carried downward through the ignition passages 33 and 34 and through the powder charge chambers 22 to ignite the propellant charges 25 therein. When the pressures in the powder charge chambers 22 develop to a value suiiicient to shear the walls 24, which pressures develop substantially instantaneously, the walls 24 and the projectiles i8 which rest against the same, are propelled outwardly from the barrels I1 at high velocity to perforate and penetrate the walls of the well, including the casing which may be set therein.

In the alternative form of the invention shown in Fig. 3, I show parts bearing similarity to parts previously described. Accordingly, these parts will be indicated by numerals previously employed having the suiiix a applied thereto. The

gun body Illa of Fig. 3 has radial barrels |111A to receive projectiles Isa, the inner ends of which project into the forward ends of powder chambers 22a formed in amagazine |91: which is received in the axial chamber |2a of the body Illa. The rear ends of the powder chambers 22a are closed by walls 36 integral with the magazine |9a and displaceable walls are formed in the forward portions of the powder chambers by cups r24a. in-

sertable in the front end portions of thepowder chambers 22a after propellant charges 25a are placed therein. The barrels |1a may be sealed by use of rubber plugs 38.

The uppermost powder chamber 22a, Fig'. 3, is arranged to receive ignition products from the firing of a priming charge through an ignition passage 33a, and the chambers 22a'are connected by'ignition passages 34a arranged so that the upper or forward ends thereof communicate with the chambers 22a adjacent theside walls of the cups 24a, so that the cups act as means for delaying the transmission of the ignition effect from each of the chambers 22a to the succeeding chamber 22a. Before the ignition effect, such as flame and/or pressure, can pass-into the upper end of a passage 34a, the cup 24a and the projectiles |8a seated therein must be displaced outwardly. In this manner, 'a sequential ring ofthe propellant charges 25a is accomplished.

In the form of the invention shown in Figs.

4 and 5, the arrangement and cooperation of parts is the same as that as shown and described with relation to Fig. 3, with the exception the body Illa and the external surface of the magazine |9a. As shown in Fig. 5, an upper ignition passage 33a is provided through which the ignition flame or pressure is carried to the uppermost powder chamber 22a to ignite the propellant charge 25a therein. A radial ignition passage section 40 connects the uppermost powder chamber 22a with a groove 4| cut in the external surface of the magazine |9a. The lower end of the groove 4| communicates with the next downwardly succeeding powder charge chamber 22a through a radial passage 42. The ignition passage 40, the groove 4|, and the passage 42 form a series passage connection between the two uppermost powder chambers 22a through which the ignition iiame and/or pressure may pass. By the use of similar radial holes or passages 40a and 42a and interconnecting grooves 4|a, the powder charge chambers 22a arranged in the magazine |9a below the uppermost chamber 22a, are interconnected in series.

I claim as my invention:

l. In a perforating gun of the character described, the combination ofza body having an axial chamber with an opening at least at one end thereof, said body having a radial barrel to receive a projectile; a magazine arranged to be entered into said chamber through said opening thereof, said magazine having a powder chamber operatively alignedwith said barrel for receiving a propellant charge for propelling the projectile, and an ignition passage communieating with said powder chamber, the internal wall of said body and the external wall of said magazine being cooperatively formedI so as tov produce an extension of said ignition passage;

a displaceable wall disposed between the pro jectile and the propellant charge; and means operative to apply an ignition eiect to said ex-' ing' thereof, said magazine having a powdery chamber operatively aligned with said barrel for receiving a propellant charge for propelling the projectile, andan ignition passage communicating with said powder chamber, the internal wall of said body and the externalwall of said magazine being cooperatively formedso as to produce an extension of said ignition passage; and means operative to apply an ignition effectv to saidk extension so that it`will be carried through said ignitionpassage to re said propellant charge.

JAIVIES O. TOW.

REFERENCES CITED The following references are of record n the ille of this patent:

UNITED STATES PATENTS 

